When looking up a lower object in multiple branches, especially for directories, ignore any existing entries whose type is different than the type of the first found object (otherwise we'll be trying to, say, call readdir on a non-dir inode). Signed-off-by: Himanshu Kanda <hkanda@xxxxxxxxxxxxxxxxx> Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx> --- fs/unionfs/lookup.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-) diff --git a/fs/unionfs/lookup.c b/fs/unionfs/lookup.c index b9ee072..755158e 100644 --- a/fs/unionfs/lookup.c +++ b/fs/unionfs/lookup.c @@ -256,6 +256,19 @@ struct dentry *unionfs_lookup_backend(struct dentry *dentry, continue; } + /* + * If we already found at least one positive dentry + * (dentry_count is non-zero), then we skip all remaining + * positive dentries if their type is a non-dir. This is + * because only directories are allowed to stack on multiple + * branches, but we have to skip non-dirs (to avoid, say, + * calling readdir on a regular file). + */ + if (!S_ISDIR(lower_dentry->d_inode->i_mode) && dentry_count) { + dput(lower_dentry); + continue; + } + /* number of positive dentries */ dentry_count++; -- 1.5.2.2 - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html